Generally, seats are provided in a car so that an occupant can sit on a front side and a rear side including the driver's seat, and the seats are configured to be movable forward and backward in a longitudinal direction of the vehicle so as to a comfortable state depending on the physical conditions of the occupant.
Conventionally, there are a manual method and an automatic method as the method of adjusting the position of the seat. The type of manually moving the seat maintains the state in which a seat frame is coupled to a vehicle body by a latch, and performs the position movement in a manner of releasing the catching by manual operation of a lever to apply a force to a required suitable position.
However, since such a manual seat moving apparatus makes a user feel uncomfortable and is extremely dangerous when it is necessary to move the seat during driving, recently, an automatic moving seat (hereinafter referred to as an “electric seat”) which is easily moved by the switch operation has attracted attention.
The electric seat is provided to allow a posture change and movement using a motor, apart from the conventional mechanical operation. In addition, a driving posture memory system function which stores the seat's position and posture set by the user in advance for each user, and adjusts the position and posture to be suitable for the user only by simple operation when the user changes has been applied. Basically, the electric seat for achieving such a function is capable of moving the entire seat forward/backward (sliding forward/backward), is capable of moving the backrest forward/backward (reclining forward/backward), and is capable of adjusting the front and rear height of the seat (front height up/down, rear height up/down).
However, in achieving each function of the conventional electric seat, when reaching the terminal end of the rail during the forward and backward movement of the seat, there has been a case where jamming has occurred on the rail, or due to friction with the adjacent structure, there has been a case that an output shortage has occurred. In order to solve, when the output has been driven in the always maximum output state, there has been a problem that shock has occurred at the time of achievement of the function, hampering convenience.
The matters described as the above background art are for promoting the understanding of the background of the present invention and should not accepted to be admitted to correspond to the related art already known to those having ordinary knowledge in the technical field.